Grow Medium - Terra Professional by Canna

I have never used that mix but I usually mix 3 parts potting soil with 1 part pearlite. Your plant should not need any additional nutrients until about the 5th node. When starting to add nutrients start VERY mild. I will start with 10-20% the recommended amount and watch the plant to see if it needs more. It is better to use too little because you can always add more later. For me the green leaf color is a good indicator. If the bottom older leaves are getting lighter green or yellow it might be time for nutrients. If your leaves are really dark green or have yellow/brown tips then they might have gotten too many nutrients.

From what I read your good for your first week of growth. But I wouldn't start feeding until you notice they need a little food added. Cheers